This invention relates to improved lubricant distributing vanes for use as part of a unitized wheel hub and bearing assembly. The unitized wheel hub and bearing assembly is for being secured on the end of vehicle axle such that a wheel can be mounted on the assembly and rotate with respect to the axle. The improved vanes are provided in a lubricant cavity of the hub assembly to redirect lubricant distribution to axially-spaced bearings within the cavity to insure adequate lubrication and cooling of the bearings.
In wheeled vehicles of all types, it is necessary to provide bearings for axles so that associated wheel hubs may rotate freely on the end of a relatively stationary axle. Such bearings must be lubricated and seals are required to retain the lubricating medium whether it be grease or oil. Frequently, wear sleeves are employed to prevent undue wear of the axle by the seals. Sometimes, such wear sleeves have been separate elements and sometimes they have been an integral part of a unitized seal.
Until quite recently, such bearing, seal and wheel hub means have been assembled piece by piece. The bearing races have been fitted to designated axle portions and corresponding portions of the associated wheel hub. The bearing elements are usually spaced as far apart axially as possible with a tapered axle portion between these elements. The assembly also includes one or two seals, depending upon the particular design. These wheel hub assemblies have typically provided long lasting performance when assembled properly. However, such an assembly process requires skilled personnel and proper equipment to achieve proper installation and operation. If repair or replacement of any part becomes necessary, correct positioning and adjustment of all elements becomes even more of a challenge and damaged parts are a quite likely result.
A non-unitized wheel hub assembly requires the components to be assembled and installed on site by a mechanic working on an axle spindle. The nature of the assembling process, and the generally horizontal orientation of the spindle during assembly, makes it difficult to fill the assembly with a liquid such as oil and the non-unitized wheel hub assembly must be lubricated with packing grease or oil filled after installation. Therefore, there was a need for a unitized wheel hub assembly which allows the assembly to be pre-filled with oil to achieve superior lubrication characteristics in contrast to the non-unitized assemblies.
More recently, some efforts have been made to develop assemblies which permit more of the various elements to be pre-assembled and adjusted, thus resulting in less dependence on the skills of the field mechanic. One such attempt has been the SAF Euro-axle developed by the Otto Sauer Achsenfabric of Keilber, Germany. These units accomplish much in terms of allowing factory assembly and adjustments of sealed bearing units and avoidance of so much dependence on the skills of the field mechanic. However, these units are not constructed to allow prefilling with oil which is a preferred bearing lubricant as compared to grease. More significantly, a special axle is included in the assembly and the pre-assembled units cannot be adapted to the millions of existing axles presently in service.
Another recent effort at development of pre-assembled and pre-adjusted sealing bearing units has been made by SKF Sweden. However, as with SAF units described previously, the SKF units are not adapted to prefilling with oil lubrication and they are not adaptable to the millions of existing axles. Furthermore, since the bearing units are more closely located relative to one another, there can be a tendency toward lessened wheel stability in operation.
Another effort at development of pre-assembled and pre-adjusted sealing bearing units which are prefilled with oil lubrication is illustrated in U.S. Pat. No. 5,328,275 assigned to Stemco Inc., the assignee of the present disclosure. These units also provide the advantage of being adaptable to the millions of existing axles. In addition, they include lubricant distributing vanes for redirecting lubricant to the bearings. In U.S. Pat. No. 5,904,427, also assigned to Stemco, Inc., there is shown a unitized wheel hub and bearing assembly including lubricant distributing vanes for redirecting lubricant to bearings within the assembly.
The present disclosure is directed to improved lubricant directing vanes for use in a unitized wheel hub and bearing assembly.